Conventionally, batteries such as lithium ion secondary batteries are formed by sealing the power generating elements which carry out charge/discharge with an exterior material. A power generating element is, for example, configured by alternately stacking multiple negative electrodes and bagged electrodes, which are formed by sandwiching a positive electrode with a pair of separators. In a bagged electrode, short circuiting with the negative electrode that is adjacent across a separator is prevented, by suppressing the movement of the positive electrode by bonding the two ends thereof (for example, refer to Japanese Laid-Open Patent Application No. 1997-320636). In addition, there are those that use ultrasound for bonding the components of a secondary battery (for example, refer to Japanese Laid Open Patent Application No. 2012-59696).